Construction Of Axial Flow Pump

Sep 29, 2024

Axial flow pumps can be classified into fixed, semi adjustable, and fully adjustable types based on the blade fixation and adjustment methods.
The semi adjustable vertical axial flow pump consists of main components such as impeller, inlet horn pipe, guide vanes, outlet bend pipe, and shaft sealing mechanism. The flow channel between the guide vanes is in a diffusion shape, allowing the water flowing out of the impeller to flow into the outlet bend from an oblique direction to an axial direction. This not only eliminates the energy loss caused by water rotation, but also converts a portion of the kinetic energy of the water flow into pressure energy, thereby improving the efficiency of the water pump. To prevent the pump shaft from swinging during operation, two guide bearings are generally installed at the upper and lower ends of the shaft. Its material is mostly made of water lubricated rubber or nylon. When the pump extracts mixed water, in order to prevent mud and sand from wearing the bearings and shafts, a specialized water system should be used for lubrication to extend its service life. The blades on the impeller can be adjusted in their placement angle according to the required flow rate and head size. When adjustment is needed, loosen the blade adjustment nut fixed to the hub and rotate the blades to the desired inclination angle.
The fully adjustable impeller is designed to change the installation angle of the blades through a set of oil pressure adjustment mechanisms, which can be carried out without stopping the machine. The mechanism is relatively complex and is often used in large axial flow pump stations.
Fixed impeller axial flow pump is a small axial flow pump (impeller diameter is generally below 250mm), with blades and hub cast as a whole, simple structure, low head (2-5m), and small flow rate (100-600m ³/h), suitable for small water lifting irrigation on flat terrain on both sides of rivers and canals.